Here are a few doctors in So Cal with Port Wine experience. They come highly recommended from folks on the mailing list over at birthmarks.com....
Dr. Gary Lask - has an office in Encino and works out of UCLA
Dr. Allan Wirtzer - Woodland Hills
Dr. Stuart Nelson - Beckman Laser Institute, UC Irvine
Dr. Bruce Achauer - Beckman, as well as a private practice in Orange. For their contact info, check out the website:http://www.birthmarks.com/doclistusa.cfm?State=CA